Space Shuttle Atlantis launched on its final mission, designated STS-135, on July 8, 2011, at 11:29 AM EDT. Liftoff occurred from the Kennedy Space Center in Florida, carrying a crew of four astronauts: Commander Christopher Ferguson, Pilot Doug Hurley, Mission Specialist Sandra Magnus, and Mission Specialist Rex Walheim. The primary objective of the mission was to deliver supplies, equipment, and science experiments to the International Space Station (ISS). Atlantis was the last of the fleet of space shuttles that had been in operation since 1981, with STS-135 representing a significant milestone in the history of human spaceflight.

During its 13-day mission, Atlantis completed several successful spacewalks and delivered more than 8,000 pounds of cargo to the ISS. This included the Permanent Multipurpose Module (PMM), which provided additional living and working space for the ISS crew. The shuttle's return marked the end of an era, as it symbolized the transition from shuttle-era missions to a new chapter in U.S. space exploration, emphasizing commercial space ventures and international collaboration.

The mission concluded with a safe landing at the Kennedy Space Center on July 21, 2011. Atlantis completed a total of 33 missions, contributing significantly to scientific research and advancing technologies in space exploration. The retirement of the shuttle program opened discussions about future missions and the role of private enterprises in space travel, reshaping NASA's approach to human exploration beyond low Earth orbit.